1IPGP - Institut de Physique du Globe de Paris (IPGP, 1 rue Jussieu, 75238 Paris cedex 05 ; Université Paris Diderot, Bât. Lamarck A case postale 7011, 75205 Paris CEDEX 13 - France)
Abstract : The semiannual and annual lines in a long series of magnetic observatories daily values, as well as in the aa-activity index series, are investigated. For both periods, amplitudes and phases of the lines corresponding to the different series present grossly common variations on decadal time scales; relative phases and amplitude ratios between the observatories change with the same time constants. The results are briefly discussed with regards to commonly received theories of the semiannual variation of magnetic activity , and some possible mechanisms for the observed geographical variability are suggested.
https://hal-insu.archives-ouvertes.fr/insu-01409778 Contributor : Eva FareauConnect in order to contact the contributor Submitted on : Tuesday, December 6, 2016 - 11:27:37 AM Last modification on : Tuesday, November 16, 2021 - 4:45:22 AM Long-term archiving on: : Tuesday, March 21, 2017 - 10:24:11 AM
M Le Mouël, M Blanter, A Chulliat, M Shnirman. On the semiannual and annual variations of geomagnetic activity and components. Annales Geophysicae, European Geosciences Union, 2004, 22, pp.3583-3588. ⟨10.5194/angeo-22-3583-2004⟩. ⟨insu-01409778⟩